1. Field of the Invention
The present invention relates to a semiconductor device and a designing method thereof, and also concerns a designing device for carrying out such a designing method.
2. Description of the Background Art
In general, in a manufacturing process of a semiconductor device, a photolithographic printing technique is sometimes used. More specifically, as illustrated in FIG. 17, a mask 5 having a predetermined pattern is formed on a removable layer 6, and light is directed to this so that a portion of the removable layer 6 that is not covered with the mask 5 is denatured and removed therefrom.
In this case, however, when there is a difference in the density depending on the portions of the pattern of the mask 5 as illustrated in FIG. 17, at a thin portion, light tends to farther proceed to reach the rear side of the mask 5 due to the occurrence of light diffraction, interference, etc., resulting in degradation in the precision of the resultant pattern (hereinafter, referred to as “patterning precision”). Consequently, the width of wiring to be formed sometimes becomes narrower than preliminarily planned. In a conventional manufacturing method for a semiconductor device which has widths of wiring such as 0.35 μm and 0.25 μm, the influence has not been so serious. In recent years, however, as the wiring becomes finer, and wiring having a width of not more than 0.18 μm has come to be produced. In the case of the production of such fine wiring, this problem has come to cause a reduction in the yield, and can not be neglected.
In order to solve the above-mentioned problems, the objective of the present invention is to eliminate the difference in density of a mask in the photolithographic technique, and another objective is to prevent a new structure, installed so as to eliminate the difference in density, from causing cross-talk noise.